FAYETTEVILLE (AP) — Arkansas put football coach Bobby Petrino on paid leave Thursday after he failed to disclose he had been riding with a female employee half his age when his motorcycle skidded off the road over the weekend.

Petrino apologized and said he had been concerned about protecting his family and keeping an “inappropriate relationship from becoming public.”

“I will fully cooperate with the university throughout this process and my hope is to repair my relationships with my family, my athletic director, the Razorback Nation and remain the head coach of the Razorbacks,” he said in a statement issued by the university.

Athletic director Jeff Long announced the decision at a late-night news conference and said he had no timeline in determining the 51-year-old Petrino’s future with the Razorbacks.

“I’m at the beginning of the review. I don’t know what I’m going to find,” Long said.

Long said he was disappointed that he didn’t hear about the passenger — former Arkansas volleyball player and current football program employee Jessica Dorrell, who is 25 — until Petrino called him Thursday afternoon, minutes before a police report was released that disclosed her presence at the accident.

Long said assistant head coach Taver Johnson has been put in charge of the program while he conducts a review that could lead, based on conduct clauses in Petrino’s contract, to a possible suspension or firing.

“I hope to have a resolution soon,” Long said. I certainly don’t have all the answers here tonight, as we meet. But again, I have an obligation and responsibility to obtain the information and then act appropriately on that information.”

Petrino, who is married with four children, didn’t mention he had a passenger during a news conference on Tuesday, two days after Sunday’s accident, and a school statement that day quoted Petrino’s family as saying “no other individuals” were involved.

Petrino said then that he had spent Sunday with his wife, Becky, at a lake and was going for an evening ride.

“When I came out of the ditch, there was a lady there that had flagged down a car,” Petrino said Tuesday, nursing four broken ribs and wearing a neck brace to support a cracked neck vertebra. “The guy that was in the passenger’s seat said, ‘Get in, we’ll just take you right to the hospital instead of waiting,’ and so I got in the car and they headed toward Fayetteville.”

In Thursday’s statement, Petrino acknowledged that he had kept quiet about Dorrell.

“I have been in constant pain, medicated and the circumstances involving the wreck have come out in bits and pieces. That said I certainly had a concern about Jessica Dorrell’s name being revealed,” he said. “In hindsight, I showed a serious mistake in judgment when I chose not to be more specific about those details,” he said. “Today, I’ve acknowledged this previous inappropriate relationship with my family and those within the athletic department administration.”

Dorrell, who did not return a call seeking comment, was hired March 28 by Petrino as the student-athlete development coordinator after serving as a fundraiser in the Razorback Foundation. She is in charge of organizing the recruiting process for the football team, including initial eligibility for each incoming player.

Long said he had not decided whether to suspend Dorrell.

Petrino signed a new seven-year contract in December 2010, after completing his third regular season at Arkansas. The contract, which was for an average of $3.53 million annually, had a clause in it that would allow Arkansas to dismiss Petrino for “engaging in conduct, as solely determined by the university, which is clearly contrary to the character and responsibilities of a person occupying the position of head football coach or which negatively or adversely affects the reputation of the (university’s) athletics programs in any way.”

The police report said Petrino was riding with Dorrell when he lost control of his motorcycle. Dorrell said in the report that she wasn’t sure what caused the accident, during which Petrino was unable to maneuver a turn and laid the motorcycle down on its left side while sliding off a rural, two-lane highway about 20 miles southeast of Fayetteville.

Petrino said in the report that wind and sun caused the accident. The police report said Petrino and Dorrell were taken by a passer-by from the scene of the accident to a shopping center in southeast Fayetteville, where a state police officer took Petrino to the hospital.

The police report said Dorrell wasn’t taken to a hospital, and that she was dropped off at her vehicle at the shopping center. State police spokesman Bill Sadler said Petrino didn’t try to hide Dorrell’s part in the accident when questioned on Tuesday.

“Coach Petrino was as cooperative as anybody that we could ever hope to encounter following the traffic crash,” Sadler said. “He was very forthcoming with information when approached by the trooper who made the initial contact Tuesday afternoon.”

Petrino, who wasn’t wearing a helmet, was hospitalized, but has since returned to practice. He will not be cited for the accident that occurred near the small town of Crosses on a road popular with motorcyclists. Petrino has said he has been an avid rider since he was 10, and the Helena, Mont., native said several years ago that he owned a Harley-Davidson and four other motorcycles.

Petrino just completed his fourth season with the Razorbacks, who have developed into a national contender under his watch. He’s 34-17 in four seasons at the school, 21-5 over the last two, and the Hogs finished last season ranked No. 5 after losing only to national champion Alabama and runner-up LSU.

Petrino is a former NFL coach, leaving the Atlanta Falcons after 13 games in the 2007 season to join the Razorbacks. He endured plenty of criticism on his way out of Atlanta, from fans and former players alike, for leaving midseason.

He was a college head coach at Louisville before that, guiding the Cardinals to a 41-9 record from 2003-07.